This week brought the Heartland Institute’s Fourth International Conference on Climate Change to Chicago. That may sound like last December’s climate conference in Copenhagen, but this gathering of scientists and policy-makers is unlike any other in the mad and often maddening world of global-warming debate. What separate’s Heartland’s gathering from the more famous Intergovernmental Panel on Climate Change’s doom-fests is that Heartland’s conference actually features a diversity of opinions and conclusions. It’s science the way it ought to be.

By and large, the mainstream media does it best to ignore the Heartland conference, since it’s far easier to dismiss something out of hand than to actually evaluate the arguments presented. Happily, this is increasingly not the case for the rest of the nation. This was Heartland’s biggest conference yet, attracting a number of politicians from across the country, bloggers and media from around the world and a surprising number of average Joes who are frustrated with the fallacy of “scientific consensus” about climate change and decided to further their personal climate-science education.

There are a number of misconceptions that progressives and environmentalists toss about when it comes to the Heartland conference, in an effort to smear the event so people don’t listen to the science that’s being presented. Let’s deal with a few of those myths up front. Heartland is not funded by Exxon-Mobil, Koch Industries, or Richard Scaife. In fact, Heartland hasn’t taken any money from any of them for years and – as a matter of policy – doesn’t not allow any group or industry sector to provide more than five per cent of its funding. The sponsors of the conference (some of which do have ties to industry) don’t pay for that privilege. It’s rather the other way around: Heartland subsidizes their attendance in a number of cases. The scientists and policy-makers at the conference aren’t in the pocket of the energy companies either. Respected, distinguished scientists like ex-NASA climatologist Dr. Roy Spencer, MIT atmospheric physicist Dr. Richard Lindzen, University of Colorado atmospheric scientist Dr. William Gray and a host of others are independent voices of integrity and sanity when it comes to climate research.

Most important, there’s no marching in lockstep among these brave dissenters. Opinions vary, as they should in a field so intricately complex and poorly-understood as global climate. There’s no “consensus” at the Heartland conference. That’s a refreshing, invigorating atmosphere when one is used to being beaten about the head over and over again with the same, tired arguments that some alarmists wield like a club. There’s a decidedly friendly, open-minded tone to this conference, at once intellectually challenging and entertaining. The global warming argument, such as it is, is often advanced using this sort of statement: “human activities are causing catastrophic climate change.” That over-simplification disguises at least five, more subtle arguments, each of which is critical to making the case that mankind ought to reduce greenhouse gas emissions in order to avoid planetary disaster. These are: 1) the climate is changing, 2) that change is alarmingly different than changes in the past, 3) that change is not occurring naturally, 4) greenhouses gases generated by mankind can affect the planet’s climate, and 5) it can therefore be proven that greenhouse gases generated by humans actually are affecting the planet’s climate in an unprecedented, catastrophic manner. The experts and policy-makers attacked at the Heartland conference tackled each of these issues, in accordance with their particular expertise.

No one, on any side of this debate, disputes proposition number one. As Professor Bob Carter of James Cook University (Queensland, Australia) adroitly put it: the phrase “climate change” is a tautology. You can’t have climate without change. The climate today is different than it was fifty years ago, fifty centuries ago and fifty millennia ago. Is the climate changing? Of course it is. That’s what climate does. Some scientists at the Heartland conference even presented evidence that we’re about to enter a significant cooling phase. That did not appear to be the majority view, but everyone I listened to agreed on the basic point: climate does indeed change, whatever mankind does or does not do.

The importance of proposition number two, that today’s changes are markedly different from historical climate changes depends on a couple of things, a) how far back you are willing to look, and b) how much faith you place on a given temperature record data set. The shorter the “look back” the more alarming recent climate changes appear. Viewed over geologic time spanning millennia, today’s variations are trivial. If one considers only the past century and a half or so, and if one ignores several troubling issues with temperature records over that period of time, today’s changes appear much more worrisome. This is a tough one to argue for the alarmist set and I’m not sure why they spend so much time trying to argue it. You can’t write off Ice Ages.

Proposition three is the most important battleground issue in this debate. Nobody disputes the fact that we experienced a warming cycle from about 1970 through 1998 and that this trend has since leveled off. Scientists like Phil Jones and Michael Mann attribute that warming trend to greenhouse gas emissions. Other scientists like Roy Spencer, Richard Lindzen, Jay Lehr and

Chris De Freitas used the Heartland conference to advance their arguments that natural forces have dominated, and will continue to dominate the climate picture. Using satellite and weather balloon data, contrasted against gaping flaws in the surface temperature record, Spencer, Lindzen and Lehr argued that greenhouse gases have a weakly negative feedback effect on climate. “Feedback” is the key here, because no scientist on any side of this debate believes that carbon dioxide and other greenhouse gases generated by man can directly influence planetary climate to a large degree. Rather, as the theory goes, the climate is so sensitive that a small increase in greenhouse gases will “force” stronger greenhouse gases – chiefly water vapor – to retain more heat in the atmosphere. However, an increasing body of data suggests that the opposite is true. Spencer has long advanced the theory that cloud over (which reflects sunlight and therefore has a cooling effect) is the misunderstood, underestimated factor in the global climate equation and that increased greenhouse gas concentrations marginally enhance this effect.

The scientific community has long recognized that the “El Nino Southern Oscillation” (ENSO) has a big effect on the climate, the only question is: how much? ENSO refers to the heat absorbing/heat releasing cycle associated with the Pacific Ocean. Phil Jones, Michael Mann and the like believe that ENSO explains roughly thirty per cent of recent global warming. Chris De Freitas presented a peer-reviewed paper that suggests that ENSO is responsible for about eighty per cent of the temperature rise. If one combines the importance of clouds with ENSO effects, there is a strong case to be made that recent temperature increases are largely – if not entirely – natural and that conclusion would rip the heart out of anthropogenic global warming theory.

No serious scientist disputes proposition number four, that greenhouse gases generated by man can affect the climate, it’s simply a question of how much. That question leads us to proposition number five. Most (though not all) alarmists rely on the surface temperature record to “prove” the case that human activities have been unduly influencing planetary temperatures. The invaluable work of Anthony Watts, and others, has shown how deeply flawed the surface temperature record really is. Moreover, as Spencer and some his colleagues have demonstrated, the atmospheric temperature record – the one that really matters – tells a much different story.

If cap and trade loving policy-makers and alarmist researchers were really serious about this issue, they would have been at the Heartland Conference, learning, discussing and exchanging information. One prominent scientist who continues to believe in AGW, Dr. A. Scott Denning of the Colorado State University, did show up and, at the end of the conference, he asked to address the crowd of skeptics that had gathered for the closing ceremonies. While Denning didn’t back off his basic positions, he did say that “it’s really too bad that more of my colleagues in the scientific community didn’t attend this…” and that “we have much more in common than our differences…” while calling for more discussion and less name-calling on all sides of the debate. (You can watch his remarks here). Kudos to Dr. Denning for doing what scientists are supposed to do: keeping an open mind. Would that more of his colleagues and the politicians pushing for climate change legislation did the same.